.text
.code16
start:
  mov $0x1010, %bx
  mov %bx, %es

  mov $0x3f8, %dx

  mov 0x100, %al
  out %al, %dx # ds<<4+0x100, get B

  mov %es:0x100, %al
  out %al, %dx # es<<4+0x100, get C

  hlt

.org 0x100
  .byte 0x42 # B
.org 0x200
  .byte 0x43 # C
